The present invention relates to a programmable logic control (PLC) device, and more specifically, to a PLC device provided with a high speed input/output module capable of processing an input/output signal at high speed.
A PLC device processes a sequence program by receiving an input signal and outputting an output signal as a result thereof, and repeatedly executes this cycle. A scanning time (process time) of the sequence program is usually about several milliseconds to one hundred milliseconds. Most controls are executed during that time, but some controls must be partially processed at a very high speed, e.g., in a very short time such as one millisecond or less.
Conventionally, a special unit is provided for the high speed processing, wherein a signal is transmitted between the special unit and a PLC device for effecting an overall control.
This special control unit, however, is cumbersome as a system and requires a large space for the installation. Further, an interface between the PLC device and the special unit is complex.